Thoroughly Modern Millie is a 1967 American musical romantic comedy film directed by George Roy Hill and starring Julie Andrews. The screenplay by Richard Morris, based on the 1956 British musical Chrysanthemum, follows a naïve young woman who finds herself in a series of madcap adventures when she sets her sights on marrying her wealthy boss. The film also stars Mary Tyler Moore, Carol Channing, James Fox, John Gavin, and Beatrice Lillie.

The soundtrack interpolates new songs by Jimmy Van Heusen and Sammy Cahn ("Thoroughly Modern Millie", "The Tapioca"), and Jay Thompson ("Jimmy") with standard songs from the 1910s and 1920s, including "Baby Face" and "Jazz Baby". For use of the latter, the producers had to acquire the rights from General Mills, which had used the melody with various lyrics to promote Wheaties for more than 40 years.

The film was nominated for seven Academy Awards and five Golden Globe Awards. It became the eighth highest-grossing film of 1967 in North America. In 2000, it was adapted into a stage musical of the same name.